Probability of Successful transmission

Question

Q If probability of frame reaching safely is 0.1 then mean number of transmissions of a frame to make it success is _____.

How to solve this question?

Comments

I tried like this -

first transmission successful - 0.1

first failed transmission then - 0.9+0.1(X) , where X is expected number of trials

then , X=0.1+0.9+0.1(X)

solving this i got - 10/9 $\approx$1.11

Answer 1

mean number of transmissions of a frame to make it success = 1/0.1

                                                                                                          =10

Comments

Thank you...:)

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how ?

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We will first send 1 frame, 0.1 will reach safely and 0.9 will not so will send it again and this goes on.

following this we will get a infinite GP as 1+0.9+0.9^2+....

After solving this we get 10.(sum of infinite GP= a/(1-r))